Investigation of Some Soil Physical Quality Properties in Different Land Uses in Bardeh Catchment, Shahrekord (Chaharmahal and Bakhtiari Province)

The type of landuse greatly affects soil properties. Assessing the effects of landuse on soil quality properties, helps to identify sustainable management practices and to prevention soil degradation. The landuse change, such as cutting forest trees and the grasslands conversion to agricultural lands destroys natural ecosystems, also causes current or future production capacity reduction and these are harmful effects on the soil physics characteristics. Considering the wide variation of land use in Iran and the fact that the values of soil quality properties are not the same in different regional conditions, this study was conducted to study the soil quality properties, especially physical soil properties, in different landuses in a part of Shahrekord. This research is located in a part of the Bardeh catchment area with an area of 80 km2 in 40 km northwest of Shahrekord (the center of Chaharmahal and Bakhtiari province). The main landuse in this area is natural pasture and dryland farming. 85 soil samples was done randomly (0-20 cm) and compound sample with distances of 1 km in pasture, dryland and irrigated farming. Considering the map of area landuse 58, 17 and 10 top soil samples were collected respectively from pasture, dryland and irrigated farming. In addition, at each sampling site, undisturbed soil samples were obtained to determine soil bulk density and saturated hydraulic conductivity and some physical characteristics such as soil particle size, bulk density, total porosity, stability of soil structure indicators and saturated hydraulic conductivity were measured in them. Statistical analysis was performed on the basis of statistical methods and using statistical software Statistica Ver.8. Analysis of variance (ANOVA) and mean comparison (Duncan method at 5% level) were used to study the soil quality characteristics in different landuses. The results showed that bulk density, Silt percentage, stability of soil structure by dry and wet method in agricultural lands (dryland and irrigated farming) is more than pasture land that did not show a significant difference. While the total soil porosity and percentage of sand in the pasture landuse is higher than those of dryland and irrigated farming. Also, in agriculture, especially dryland farming, the percentage of clay is more than the pasture landuse, but the saturated hydraulic conductivity is less that did not show a significant difference. The results of analysis of variance and the mean comparison of studied characteristics did not show a significant difference between pasture, dryland and irrigated farming. To prevent land degradation and soil quality reduction, reduction the tillage operations and the addition of organic matter are recommended. In pasture lands, the grazing must be prevented prior to pasture preparation.